We report results of an investigation in the initial process of graphitization on 6H-SiC (0001) surfaces using scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED). There appeared (3 × 3) and (2 × 2) periodicities in the STM images of the 6H-SiC (0001) surface annealed at 950 and 1000°C, respectively. After annealing the 6H-SiC (0001) surface above 1300°C, many large and small domains with various periodicities were observed in the STM image. This STM image can be explained as Moiré patterns due to different combinations of two graphite layers. In consistent with the STM result, azimuthally-rotated graphite (1 × 1) spots were observed in a LEED pattern, where brightest parts in the diffraction ring define combination of two hexagonal lattices of graphite.
